Footage from video cameras in the prison block where Kenneth Burgess and Kamel Trott allegedly beat fellow inmate Dennis Robinson disappeared after the incident, a jury heard.

The Supreme Court trial of the accused men also heard that prison officers made unauthorised visits to Burgess' cell when it was meant to be secured after the incident, and items went missing.

Robinson, 38, alleges that Burgess, 36, and Trott, 32, ambushed him in his cell on June 6 last year and launched a vicious punching attack lasting an hour.

After the incident he claimed his attackers pulled a table up outside his cell and sat playing cards, leaving him left trapped and badly hurt inside.

The pair deny assault with intent to do grievous bodily harm. Yesterday's evidence about the cameras and cell visits came as prison officer Gladwin Simons, who helped escort Robinson to hospital, was quizzed by their lawyers.

In answer to questions from Burgess' lawyer Elizabeth Christopher, he detailed Burgess' complaint that items disappeared from his cell after the incident. The accused prisoner was in segregation at the time, with the cells at the centre of the investigation meant to be off-limits.

Burgess complained that officers Jason Smith and Erskine Brangman nonetheless let inmates into his cell. Officer Simons read a report into the complaint compiled by principal officer Smith. This detailed an interview with Jason Smith who said: "Yes, I let someone go into his cell, I let Roger Lightbourne put something back into his cell around the time of the Queen's Birthday Holiday."

Informed that the cell was locked for security reasons, and asked if he knew that under no circumstances were officers to unlock it, he replied: "Yes, I knew but (Erskine Brangman) had let other inmates into the cell and I told him not to, but I only let inmate Lightbourne put something back."

Informed that he may have to replace items missing from Burgess' cell, officer Smith is reported to have replied: " You can't make me pay for that. Other officers were letting inmates into the cells too."

A second prison report by the same principal officer reported officer Erskine Brangman to have responded: "Yes, I went into his cell but only to close the window."

He denied entering other secured cells or letting inmates in.

Prompted by Senior Crown Counsel Carrington Mahoney, officer Simons reviewed a document listing items replaced after Burgess' complaint, revealing in the process that one of them was a small fan. Ms Christopher had not specified during her questions what the items were, although the list was eventually tendered in evidence.

Richard Horseman, representing Robinson, asked about video cameras in the Echo 2 block where the incident happened. Officer Simons explained that one faces west and one faces east, and their control unit is located in a secure area that not all officers have access to.

"Are you aware that an attempt was made to bring back the videotape of June 6, but the footage was missing for that particular day?" inquired Mr. Horseman.

The witness replied that he was aware of the attempt, but not that the footage was missing.

A further crown witness, Florida-based DNA expert Candy Zuleger, told the jury that she tested a vest and some fabric seized from Trott's cell, and a T-shirt from Burgess' cell which had bloodstains on them.

She explained that everybody, except identical twins, has their own unique DNA. She cut the stains out of the items and compared their DNA to a sample from Robinson. A sample she was sent from Burgess was "degraded" and did not work.

The vest from Trott's cell matched Robinson's DNA profile, she told the jury, and the possibility of someone else having the same profile would be one in 160 billion in the US caucasian population and one in 24 billion in the US African-American population. The fabric from Trott's cell did not match Robinson's profile.

The T-shirt from Burgess' cell matched Robinson's profile, with what Ms Zuleger described as a one in 9.3 quintillion chance of it matching someone else in the US caucasian population and one in two quintillion of it matching someone in the US African-American population. A quintillion is a one with eighteen zeros after it, she explained, and the numbers cited are "much beyond" the six billion population of the earth.

Under cross examination from Burgess' lawyer Elizabeth Christopher, Ms Zuleger agreed that she could not say who had worn the T-shirt seized from Burgess' cell, and she could not say it had his DNA on it.

The case continues.